[prev in list] [next in list] [prev in thread] [next in thread] 

List:       r-devel
Subject:    Re: [Rd] mcmapply Core Usage
From:       Simon Urbanek <simon.urbanek () r-project ! org>
Date:       2014-05-30 1:29:31
Message-ID: 235FF4EA-FBF9-4273-886E-D67FC10408BB () r-project ! org
[Download RAW message or body]

On May 29, 2014, at 8:04 PM, Henric Winell <nilsson.henric@gmail.com> wrote:

> Simon Urbanek skrev 2014-05-29 15:06:
> > Dario,
> > 
> > yes, that is a bug, now fixed.
> 
> Thanks for fixing it.
> 
> This problem was independently reported some time ago \
> (https://bugs.r-project.org/bugzilla/show_bug.cgi?id=15016) and I believe that it \
> can now be closed. 

Ah, thanks, done,
Simon


> 
> > 
> > Cheers,
> > Simon
> > 
> > 
> > On May 29, 2014, at 2:00 AM, Dario Strbenac <dstr7320@uni.sydney.edu.au> wrote:
> > 
> > > Hello,
> > > 
> > > I have a minimal example that shows a problem I'm having with parallel \
> > > processing. 
> > > library(parallel)
> > > mcmapply(function(x, y)
> > > {
> > > print("Running")
> > > Sys.sleep(10)
> > > }, as.list(1:10), as.list(10:1), mc.cores = 16, SIMPLIFY = FALSE)
> > > 
> > > I see "Running" printed once every ten seconds. I read the documentation for \
> > > mcmapply, but I don't understand why it wouldn't print all ten output \
> > > statements almost at once, then wait for about ten seconds, then return to the \
> > > prompt. Is it documented in another location ? 
> > > My problem is that I have a section of code that takes a long time, which I \
> > > have replaced with Sys.sleep in the above example, but when I look at the \
> > > output of top, I only see 1 CPU being used. The computer has 16 processors. 
> > > > sessionInfo()
> > > R version 3.1.0 (2014-04-10)
> > > Platform: x86_64-pc-linux-gnu (64-bit)
> > > 
> > > locale:
> > > [1] LC_CTYPE=en_AU.UTF-8       LC_NUMERIC=C
> > > [3] LC_TIME=en_AU.UTF-8        LC_COLLATE=en_AU.UTF-8
> > > [5] LC_MONETARY=en_AU.UTF-8    LC_MESSAGES=en_AU.UTF-8
> > > [7] LC_PAPER=en_AU.UTF-8       LC_NAME=C
> > > [9] LC_ADDRESS=C               LC_TELEPHONE=C
> > > [11] LC_MEASUREMENT=en_AU.UTF-8 LC_IDENTIFICATION=C
> > > 
> > > attached base packages:
> > > [1] parallel  stats     graphics  grDevices utils     datasets  methods
> > > [8] base
> > > 
> > > loaded via a namespace (and not attached):
> > > [1] tools_3.1.0
> > > 
> > > --------------------------------------
> > > Dario Strbenac
> > > PhD Student
> > > University of Sydney
> > > Camperdown NSW 2050
> > > Australia
> > > 
> > > ______________________________________________
> > > R-devel@r-project.org mailing list
> > > https://stat.ethz.ch/mailman/listinfo/r-devel
> > > 
> > 
> > ______________________________________________
> > R-devel@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
> > 
> 

______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel


[prev in list] [next in list] [prev in thread] [next in thread]